四阶锁相频率合成器的环路参数设计及仿真

采用三阶环路滤波器的四阶频率合成器比三阶频率合成器能够更好的改善频率合成器的频谱杂散性能,但增加的极点会使得环路滤波器中电阻电容值的优化设计更为复杂.通过对系统的相位裕度、环路带宽、零极点频率等环路参数之间的关系,提出了一种无源环路滤波器优化设计的估算方法,并给出仿真流程.方法从相位裕度和环路带宽出发,通过指定零点和第二个非零极点所需要提供的参考毛刺的衰减程度来得出环路滤波器的各个原件值,简化了优化计算过程.

Design and Simulation of Loop Parameters of Four-Order Charge Pump Phase Locked Loop Frequency Synthesizer

Four-order frequency synthesizer with three-order loop filter has a better performance in suppressing reference spurs than three-order frequency synthesizer, however, the added pole point makes the calculation of optimization values of capacitors and resisters of loop filter more complex. In this paper, a new calculating approach of passive loop filter of four-order charge pump-phase locked loop frequency synthesizer with simulation procedure is clearly introduced to simplify design process greatly based on...